Clutch



Jne 1.6, 1942- v- B. LIVINGSTON l CLUTCH Filed Jn. 27. 1941 (Ittomxegs-b y Patented June 16, 1942 CLUTCH Donald B. Livingston, Beverly, Mass., assignor to Kinney Manufacturing Company,

Jamaica Plain, Mass., a corporation of Massachusetts Application January 27, 1941, Serial No. 376,051

Claims.

My present invention relates to improvements in clutches of the friction disc type by which coupled. In accordance with my concept, I elim,

inate back lash having its origin in the splines by providing a chamber, inclusive of the spline, for a viscous fluid which, under the influence of centrifugal force, fills the back lash voids inthe spline.

The viscous fluid is, of course, forced out yfrom the driving side of the splines, but remains as a filler under pressure for backlash voids. Since vibration frequency is relatively rapid, I am able to. provide an effective vibration dampener'byy employing as a void filler a liquid having a rela# tively low flow frequency. Such a fluid, under the pressure developed by centrifugal force, re-

mains in the voids preventing the relative motionv between the splined clutch parts normally productive of back lash.

Since in coupling the prime mover with the driven element it is impossible to establish perfect alinement, it must be assumed that to some degree angular misalinement of the drive and driven elements is always present and such misalinement, of itself, contributes more complex vibration factors.

For that reason, my present invention provides for clutch flexibility by means of a self-alining bearing and spherically faced external splines each having a common center at the axis of the shaft.

' By this construction, I provide a flexible clutch permissive of angular shaft misalinement without strain on the connecting elements and an effective vibration dampener by which long, eilicient clutch operation is ensured.

In the accompanying drawing, I have shown anY embodiment of my invention in a clutch structure, partly sectioned to permit its several novel features and advantages to be readily apprec lated.

At I Ihave indicated a hollow drive shaft and at 2 a driven shaft as typical of elements to be coupled. The drive shaft I receives the shouldered end 3 of the driven shaft 2 and is counterborcd to receive the bearing ll and the ring 5 by which the bearing il is locked between itand the split ringshoulder ,6 held in its ,groove 'I by a keeper 8 bolted to the end 3 of the shaft 2. The bearing 4 is conventional and preferably is of the self-alining type in order to provide ilexibility and ensuring eflicient clutchl operation even where the shafts are angularly misalined. While the bearing i may be conventional, the assembly just described is particularly effective in that a two-way thrust-bearing within theclutch is prou vided simplifying installation by eliminating the necessity 0f bearings externally ofthe clutch to take care of thrust factors. j

The `drive shaft I includes a flange 9 for atv tachment, for example, to the fly wheel (not shown) of a prime mover and carries a gear Ill, the. teeth of which enter between teeth II formed in the bore of the hub 'I2 ofthe clutch disc or plate I3 to slidably spline the disc. I3 toA the drive shaft I. While the disc I3 maybe otherwise splined te theshaft I, the illustrated construction is preferable in thatgears are universally available and they may be formed with spherical teeth having a center at the axis of the shaft common to the center of the self-alining bearing 4 thereby providing flexibility permitting positive clutch engagement even if the drive and driven elements are angularly misalined.

The backing plate I4 is keyed to the driven shaft 2 and slidably supports the clamping plate I5 by means of pairs of bolts I6, the ends of which support the pivots Il for the cams I8. Links I9 are pivotally connected to the cams I8 and to'the shifter sleeve 2B on the shaft 2 to actuate the cams It to draw the clamping plate I5 towards the backing plate Illto clamp the clutch disc I3 therebetween. The sleeve 2U carries a shifter ring 2l for the shifting mechanism (not shown). The clamping plate I5 is bored as at 22 intermediate each pair of bolts I5 to receive springs 23 in contact with the backing plate Ill urging the clamping plate I5 into a position wherein the clutch is disengaged.

In accordance with my present invention, I hydraulically control back lash tendencies inherent in the spline between the driving element I and the clutch disc I3. I accomplish this result by means of sealing rings 24 and 25 having annular bosses 28 and 21 to t snugly within the recesses in the hub I2 out of contact with the teeth II to define a trough preferably establishing a' pair of chambers 28 and 29 interconnected through the voids in the spline- The rings 24 and 25 carry packing seals 30 of any suitable material to seal the space between the rings 24 and 25 and the shaft l against dirt and moisture without interfering with the eXibilit-y of the clutch structure necessary to permit its eicient operation. The rings 24 and 25 include attaching flanges 3| and 32 to permit attachment to the ends of the hub I2. The hub I2 is oounterbored to receive the ange 32 while the ring 24 is provided with a.N suitable conventional grease fitting through which the viscous liquid is admitted to the chambers 28 and 29. k

The rings 24 and 25 are spaced from the Mgear I to ensure the free flow ofY the" liquid' under the influence of centrifugal force into the back lash voids in the spline and to avoid interference with clutch flexibility. To increase the capacity of the chambers 28 and 29, I have undercut the gear I0 as at 33. The capacity of the chambers' 28 and 29 must be such as to define a trough or pocket for the liquid greater than the capacity of the voids and they must be adapted s'o that when the shaft I is rotated the liquid under centrifugal force positively lls under pressure the back lash voids.

Because vibration frequency is relatively rapid, by using a liquid having a relatively low ow frequency, the voids are effectively filledv against back lash tendencies.' I' have found that a satisfactory liquid isa lubricant such as 600W or 140 S. A. E. oil. Other lubricants may be used provided that ,their flowfrequency is substantially less than the vibration frequency factors which may vary in dilferent installations. In order to ensure most efficient operation, the heaviest lubricant should be used that is fluid at the lowest temperature expected. v

Clutches in accordance with my invention are easy to install because of theirflexibility and because thrust factorsmay be disregarded and the effective dampening of back lash ensures a maximum of'eflicient service.

What I therefore claim and desire to secure by Letters Patent is:

1. A clutch comprising a drive member, a driven member and means to couple said members, said coupling means'comprising a backing plate and a slidable clamping plate carried by one of saidmembers, and a clutch plate intermediate said rst named plates, a gear carried by said drive member, said clutch platenincluding a hub having an axial bore grooved to receive the teeth of said gear to establish a spline slidably lockingsaid clutch plate to said drive member, rings attached to each end of said hub to define with said gear a pair of annular chambers and relatively restricted passages in communication with said spline, said chambers being adapted to hold, Vwhen the members are at rest, a sufli'cient volume of a viscous fluid to fill under the influence of centrifugal force the voids in'said spline to eliminate back lash productive of chatter and increased back lash.

2. The clutch ofnclaim 1 in which the'teethof said gear'are sphericalwhereby said spline permits angular misalinement of said' members and said sealing rings are spaced lfromsaidgear and, said drive member, and carry means toy s eal theI space between said rings` and s aid `drive member.

3. A clutch compri'sing'a drive member, afndriver'iv member, and means 'to couplesaid members, "s d, coupling means 'comprising a'backing platev and' a slidable cla'nfiping"plateA carried by hone ofsaid`r members, and a clutch plate intermediate said first named plates, said clutch plate including a hub having a grooved axial bore, a gear carried by the other of said members with its end exposed, the teeth of said gear entering said grooved axial bore to establish a slidable spline for said clutch plate, a pair of sealing rings each having an annular boss to fit snugly within one end of said hub bore and each having a flange for attachment to said hub establishing an annular trough defining a circular segment-shaped reservoir for a viscous liquid when the members are at rest, the width of said trough being increased between the rootdiameter of the teeth of said gear and the edgespf said flange so that said reservoir-has sufficient capacity for a volume of liquid adequateV toseal the back lash voids under the iniiuence of centrifugal force when the gear carrying member is rotated.

. 4. Theclutch, of claim 3 in which the gear .is undercut to increase the capacity of said reservoir.

5. The clutch of claimS in which the sealing ring adjacent' the endof the member to lwhich said gear isv splinediswholly within the plane dened by the end of said member..

6. The clutch ofclaim 3 inwhich onelof said members to` be coupled `is formed with an axial recess receiving tl1e',e,ndv of the other of said members and a bearing is located in said recess between said members. Y v

7., A clutch comprisinga drive member, a driven member,I one of said members having. an axial bore to receive freely the end of the other of said memberameans Yto couple said members comprising a backing plate anda slidable clamping plate carried by' one of said members, a `clutch plateA intermediate said first named plates, andY means to Yac tuate said.' coupling means a spline slidably locking said clutch plate to the other of said members, ,and atwo way thrust bearing in saidV axial bore between `said `driveand driven members, said thrust bearing'including a pair of races, each.of,said members being formed to presenta shoulder -against which one of said races is seatedV and a ring carried by' eachrone of said members toretain each of said races against its shoulder. l

8. A clutch comprising a drive member, a driven member, one ofsaid members having anaxial bore to receive freely the end of the other of said members, means to couple said members comprising a backingplate and a slidable clamping platecarried byone of said members, a clutch Iplate intermediate said `first named plates, and

means to actuate said coupling means, a spline slidab1y`locking said clutch plate ,to the other of said members, a two way thrust bearing in said axial bore between said, drive and driven members, said thrust bearing includinga pair .of,races, each of said membersbeing formed to present a shoulder iagainstwhichl one rof said races isseated and a'ring'carried by each one of said members to4 retain each of said races against its shoulder, and means 'defining a chamber for a viscous uid inclusive of saidspline, said chamber being adapted to hold a suflicient volume of said liquid to ll the voids in said spline positively when subjected to centrifugal force.

9. A Aclutch comprising a drive member, a driven memberhone of vsaid members having an ayialfbore to :receive freely the end of the other of'saidmembers, means to couple said members comprising Aa backing plate and a slidable clamping plate carried by one of said members, a clutch plate intermediate said first named plates, and means to actuate said coupling means, said clutch plate having an axial bore having grooves thereon, a gear on the other of said members, said gear having spherical teeth entrant of said grooves to establish a spline slidably locking said clutch plate to the other of said members, and a two way self-alining thrust bearing in said axial bore between said drive and driven members, said thrust bearing including a pair of races, each of said members being formed to present a shoulder against which one of said races is seated and a ring carried by each one of said members to retain each of said races against its shoulder, said spline and said self-alining bearing having a common center at the axis of said members.

10. A clutch comprising a drive member, a driven member, one of said members having an axial bore to receive freely the end of the other of said members, means to couple said members comprising a backing plate and a slidable clamping plate carried by one of said members, a clutch plate intermediate said first named plates, and means to actuate said coupling means, said clutch plate having an axial bore having grooves thereon, a gear on the other of said members, said gear having spherical teeth entrant of said grooves to establish a spline slidably locking said clutch plate to the other of said members, a two way self-alining thrust bearing in said axial bore between said drive and driven members, said thrust bearing including a pair of races, each of said members being formed to present a shoulder against which one of said races is seated and a ring carried by each one of said members to retain each of said races against its shoulder, said spline and said self-alining lbearing having a common center at the axis of said members, and means defining a chamber inclusive of said spline for a viscous liquid, said chamber being of a capacity to hold a sufficient volume of liquid to 1ill the voids in said spline positively when subjected to centrifugal force.

11. A clutch comprising a drive member, a driven member, one of said members having an axial bore to receive freely the end of the other of said members, means to couple said members comprising a backing plate and a slidable clamping plate carried by one of said members and a clutch plate intermediate said first named plates, means to actuate said coupling means, a spline slidably locking said clutch plate to the other of said members, and a two-way thrust bearing in said axial bore between said drive and driven members, said bearing and said spline each being adapted to permit angular misalinement of said members to be coupled and each having a center common to the other at the axis of said members.

12, A clutch comprising drive and driven members, a clutch member, said clutch member and one of said rst-named members having internal and external spline portions establishing a slidable connection, a pair of annular portions carried by the member having the internal spline portion adjacent opposite ends of the internal spline and establishing with said internal spline an annular trough inclusive of said slidable connection, said trough having an outside diameter substantially equal to the root diameter of said internal splinerestablishing a substantially circular segment-shaped reservoir when the members are at rest, the trough being of increased axial width intermediate the root diameter of the external spline portion and the axis of the members to make said reservoir of a capacity to hold a sufficient volume of the liquid to fill positively all the voids in the slidable connection when the members are rotated.

13. The clutch of claim 12, in which the capacity of the trough is secured by' undercutting the external spline portion interiorly of its root diameter.

14. The clutch of claim 12, in which the capacity of the trough is secured by providing said trough establishing portions with laterally disposed annular pockets.

15. A clutch comprising a drive member, a driven member and a clutch member, said clutch member and one of said first-named members including complemental internal and external spline portions establishing a slidable connection, the member having the internal spline portion including inwardly disposed portions establishing a trough having its maximum internal diameter substantially equal to the root diameter of the internal spline and defining with said external spline portion a pair of annular reservoirs having their maximum diameter substantially equal to the root diameter of the external spline and relatively restricted passages in communication with said slidable connection, said reservoirs holding, when the members are at rest, a suicient volume of liquidto ll the voids in said slidable connection under the influence of centrifugal force when the slidable interconnected members are rotated thereby to eliminate backlash productive of chatter and wear.

DONALD B. LIVINGSTON. 

